Utility of the RENAL index – Radius; Exophytic/endophytic; Nearness to sinus; Anterior/posterior; Location relative to polar lines – in the management of renal masses

Context The growing incidence of renal masses and the wide range of available treatments require predictive tools that support the decision making process. The RENAL index – Radius; Exophytic/endophytic; Nearness to sinus; Anterior/posterior; Location relative to polar lines – helps standardize the anatomy of a renal mass by differentiating three groups of complexity. Since the introduction of the index, there have been a growing number of studies, some of which have been conflicting, that have evaluated the clinical utility of its implementation. Objective To analyze the scientific evidence on the relationship between the RENAL index and the main strategies for managing renal masses. Acquisition of the evidence A search was conducted in the Medline database, which found 576 references on the RENAL index. In keeping with the PRISM Declaration, we selected 100 abstracts and ultimately reviewed 96 articles. Synthesis of the evidence The RENAL index has a high degree of interobserver correlation and has been validated as a predictive nomogram of histological results. In active surveillance, the index has been related to the tumor growth rate and probability of nephrectomy. In ablative therapy, the index has been associated with therapeutic efficacy, complications and tumor recurrence. In partial nephrectomy, the index has been related to the rate of complications, conversion to radical surgery, ischemia time, function preservation and tumor recurrence, a finding also observed in radical nephrectomy. Conclusions The RENAL index is an objective, reproducible and useful system as a predictive tool of highly relevant clinical parameters such as the rate of complications, ischemia time, renal function and oncological results in the various currently accepted treatments for the management of renal masses.